(a) Field of the Invention
The present invention relates to a liquid crystal display, and in particular, to a transflective liquid crystal display.
(b) Description of Related Art
Generally, a liquid crystal display (LCD) includes a liquid crystal panel assembly including two panels provided with two kinds of field generating electrodes such as pixel electrodes and a common electrode and a liquid crystal layer with dielectric anisotropy interposed therebetween. The variation of the voltage difference between the field generating electrodes, i.e., the variation in the strength of an electric field generated by the electrodes changes the transmittance of the light passing through the LCD, and thus desired images are obtained by controlling the voltage difference between the electrodes.
The LCDs are classified into a transmissive type LCD and a reflective type LCD depending upon whether it uses a separate backlight for a light source or an external light for that purpose. Recently, a transflective LCD operating both in a transmissive mode and in a reflective mode has been developed.
However, the transflective LCD has electro-optical characteristics depending upon the operating modes, and a given characteristic may be good for one of the two modes, while it may not be good for the other mode. For example, a cell gap and a twist angle optimized in the transmissive mode may cause the deterioration of the reflectance and the contrast ratio in the reflective mode so that the LCD may not perform a normal operation.
Furthermore, the transflective LCD has a problem of poor front transmittance and poor vertical viewing angle such that its white characteristic and contrast at about 25° up and down are radically deteriorated.